This work represents a unified modeling method for the design and the virtual test of integrated mixed-signal circuits. Compared to the state-of-the-art the advantage of this method is, that when creating the models, all model properties occurring in the design process, will be taken into account and implemented. By applying modularly structured and configurable behavior models, the requirements and tasks during the different IC development phases, like circuit design and verification or test development, can be flexible fulfilled and coped with. Moreover, different model abstraction classes have been introduced, which differ in their level of detail as well as in mapping circuit topologies. With these modeling techniques HDL models can be created, whose behavior optimally can be adjusted to specific simulation tasks and requirements, by activating or deactivating model properties, resulting in considerable time savings in the verification process. Taking an IC (antenna driver for passive entry/go systems) from the automotive domain as an example, performance gains in the circuit and in the test development phase could be proven. Hereby the performance further could be increased by developing and applying configurable MOSFET Verilog-A models, which have the feature to switch on or off specific transistor characteristics.